Dyeing cellulose esters and ethers



patented Apr. 21, 1936 UNITED sr PATENT OFFICE DYEING CELLULOSE ESTERSETHERS Arthur Howard Knight, Ashton-on-Mersey, England, assignor toImperial Chemical Industries Limited, a corporation oi Great Britain NoDrawing. Original application lune 2, 1933, Serial No. fi'id,l22..Divided and this application July 3, 1935, Serial No. 29,?29.

in which the diazo component possesses at least one nitro group are ofparticular interest, because the dyeings so obtained possess excellentiastness properties.

The dyestufis of this series are sparingly soluble in water, andareapplied to the fiber in the form of an aqueous suspension.

Suitable first components are aniline, o-cliloro-= aniline,m-chloroaniline, p-chloroaniline, cresidine, p-phenetidine, o-anisidine,p -anisidine, o=toluidine, m-toluidine, p-nitroaniline, m-nitroaniline,o-nitroaniline, m-nitro-p-toluldine, o-chloro-p-nitroaniline,5-nitro-2-anisidine, 4-mitro-Z-anisidine, m-aminobenzenesulphonanilide,p aminodimethylbenzamide, a-naphthylamine, or ,B-maphthylamine, but theinvention is not limited to these components.

The invention is illustrated but not limited by the following examplesin which the parts are by weight.

Example 1 The solution obtainedby diaaotizing 93 parts of aniline in theusual way is added slowly to a solution prepared by dissolving l22 partsof 1:3:5-- nylenol in a solution of 4,806 parts of water and it parts ofcaustic soda, adding 208 parts of sodium carbonate and adjusting thetemperature to to 10 C. When combination is complete the dyestuif whichis out of solution is filtered ofi, washed with water, and preserved aspaste. t dyes cellulose acetate in golden orange shades of excellentfastness to light whenapplied, for

example, as follows:

Enough of the dyestufi paste to contain one lb. of dyestuii is added toa lukewarm dyebath, and to this dyebath 100 lbs. of cellulose acetateyarn are then added. The temperature is raised to 80 C. duringhali anhour and the material is dyed for a further half an hour at thistemperature.

- It is then washed and dried in the usual manner,

giving a' golden orange dyeing.

In Great Britain Example 2 13? parts of p-phenetidine are diazotized inthe usual way and the solution 'so obtained. added slowly to a solutionof 1:3:5-xylenol prepared as in Example 1. When combination is completethe dyestufi which is out of solution is filtered off, washed withwater, and preserved as paste.

It dyes cellulose acetate in reddish yellow shades of excellent lightfastness when applied in the manner described in Example 1.

Example 3 The solution obtained by diazotizing 138 parts ofp-nitroaniline in the usual way is added slowly to a solution of1:3:5-xylenol prepared as in Example 1. The dyestufi so formed, which isout of solution, is filtered off, Washed with water,

i and preserved as paste. It dyes cellulose acetate in reddish orangeshades of very good light iastness.

Eaz'cmtpleel.

2% parts of m-aminobenzenesulphonanilide are diazotized in the usual wayand the solution so obtained added slowly to'a solution of 122 partsof1:3:5-xylenol prepared as in Example 1. When combination is complete thedyestufi which is out of solution is filtered off, washed with water,and preserved as paste. It dyes cellulose acetate in orange shades ofexcellent fastness to light and washing when applied in the mannerdescribed in Example 1.

' Example 5 168 parts of 5-nitro2-anisidlne are diazotized in the usualway and the solution so obtained added slowly to a solution of 122 partsof 1:3:5- nylenol prepared as in Example 1. When combination is completethe dyestufi, which is out of solution, is filtered off, washed withwater, and preserved as paste.

It dyes cellulose acetate in yellowish orange shades of very goodfastness to light and washing when applied in the manner described inExampie 1. Example 6 The solution obtained by diazotizing 143 parts ofa-naphthylamine int e usual way is added slowly to a solution of 122arts of 1:3:5-xylenol prepared as in Example 1. When combination iscomplete the dyestufi, which is out of solution, is filtered oii, washedwith water, and preserved as paste.

It dyes cellulose acetate in reddish orange shades of very good lightand washing fastness ill 2. A process for dyeing cellulose estermaterial which comprises applying thereto an aqueous suspension of anazo dye .of the general formula wherein R represents an aryl radical ofthe benzene or naphthalene series, free from sulpho-, carboxyandhydroxygroups, but containing at least one nitro group.

3. Cellulose ester and cellulose ether materials whenever dyed by an azocompound of the class obtainable by coupling a diazo-aryl compound ofthe benzene or naphthalene series, free of sulpho-, carboxyorhydroxygroups, with 123:5- xylenol.

4. Cellulose ester material when dyed with an azo dye of the generalformula wherein R represents an aryl radical of the benzene ornaphthalene series, tree from sulpho-, carboxyand hydroxygroups,but'containing at least one nitro group.

5. The process of dyeing cellulose acetate fibers which comprisesapplying thereto an aqueous suspension of the dyestufl obtainable bycoupling diazotized p-nitro-aniline with 1:3:5-xylenol.

6. The process oi! dyeing cellulose acetate fibers which comprisesapplying thereto an aqueous suspension of the dyestuff obtainable bycoupling diazotized 5'--nitro2-anisidine with 1:3:5-xylenol.

7. Cellulose acetate fibers when dyed with the dyestufl' obtainable bycoupling diazotized p-ni-. tro-aniline with 1:3:5-xylenol.

8. Cellulose acetate fibers when dyed with the dyestuff obtainable bycoupling diazotized.5-nltro-2-anisidine with l :3 :5-xylenol.

AR'rriUR HOWARD KNIGHT.

